Steam-turbine nozzle.



W. KIESER.

STEAM TURBINE NOZZLE.

APPLICATION FILED 0011, 1912.

1 1 1 2,295. Patented Sept. 29, 1914.

Fig. 2.

, WaIber- Kleser: fz 2 71' b M UNITED sTA'rns PATENT ()FFlGE.

WALTER KIESER, or BERLIN, GERMANY, nssrenon 'ro GENERAL ELECTRIC COMPANY,

- A: CORPORATION or new YORK.

STEAM-TURBINE NOZZLE.

Specification of Letters Patent.

Patented Sept. 29, 1914.

To all whom it may concern Be it known that I, VVALTEI: Kinsnn, a citizen of Switzerland, residing at Berlin, Germany, have invented certain new and useful Improvements in Steam-Turbine Nozzles, of which the following is a specification.

This invention relates to elastic fluid turbines and its object is to provide an expanding nozzle which will avoid the losses due to an imperfect or improper expansion of the steam.

The invention consists in a nozzle whose i partition walls terminate at or near to the smallest point in the nozzle, while the boundary walls extend to the exit end of the nozzle. This permits the steam to expand between said boundary walls in accordance with the existing counterressure. With decreasing counter-pressure, thestream of steam will be curved backwardly more and more after leaving the partition walls, whereby the greater ratio of expansion is given which is necessary in this case. Under some circumstances, ordinary directing devices may be used instead of nozzles, saiddevices having side walls parallel to the exit ends, which simplifies manufacture. In the case of cast nozzles, a slight enlargement of the cross-section of the steam passage beyond its smallest point can hardly be avoided for structural reasons, but this need not be determined with exactness, and so in this case also a considerablycheaper process of manufacture is obtained. The two boundary wallsof the nozzle are preferably kept parallel from the termination of the partition walls, but this is not essential.

In the accompanying drawing, Figure 1 is a section of a portion of a multi-jet nozzle having sheet metal partition walls; Fig, 2 is a section on the line 22, Fig. 1; Figs. 3 and 4 'show similar views of a cast metal construction. I

In Figs. 1 and 2, the partition walls 1 are preferably constructed of sheet metal; but whatever the material may be, they terminate at 2, which is the narrowest point in the passage for the steam through the nozzle.

and some distance back from the exit end thereof. The boundary walls 3, 4 are carried beyond the ends of the partitions to such an extent that the desired expansion of the steam is obtained in the nozzle. evenat the lowest counter-pressure. The depth of the boundary walls beyond the ends of the partitions will vary, depending upon whether or not a supplementary expansion is permitted in the gap between the nozzles and the bucket wheel. The boundary walls are preferably parallel.

In Figs. 3 and 4, the partitions 5 and boundary walls 6, 7 are of cast metal, being preferably integral. The partitions run only a short distance beyond the narrowest point 8, and the boundary Walls may be either parallel or slightly divergent from this point, or even converge slightly, if found necessary. If divergent, then the enlargement of the nozzle thereby produced should be only so great that at the smallest desired expansion the space between the walls 6, 7 beyond the ends of the partition is nevertheless filled with steam.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understoood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. A steam turbine nozzle having its boundary walls extending to its outer end, and its partitions terminating at a distance from the exit end of said nozzle sufliciently far to permit the steam to expand to substantially the true counterpressure before emerging from between said boundary walls.

2. A steam turbine nozzle for varying counterpressure, having its boundary walls extending to its outer end, and its partitions terminating adjacent to the narrowest point in said nozzle, said pointlying sufliciently far from the outer end to permit the steam to expand within the nozzle to substantially the true counterpressure.

-3. A steam turbine nozzle for varying counterpressure having boundary walls extending to its exit end and partition walls exit end to permit free expansion of the steam in the nozzle to substantially the true counterpressure under all conditions of operation, the distance apart "of the adjacent surfaces of adjacent partitions being uniform for a substantial distance back from their ends.

In witness whereof, I have hereunto set my hand this 16th day of September, 1912. 1 WALTER KIESER.

Witnesses LUDWIG CUBELIO, CARL BITTER. 

